The Sprint: This Astron Sprint is from the original '70s kit. It uses streamer recovery, but I changed it out for a small 8" parachute. It is designed for high-performance altitude flights, and generally requires longer-burning ejection delays for maximum height. The engine must be tape-friction-fit as this model does not have a metal motor clip. Instead it has the boattail end designed to reduce drag. This rocket was later given my "Iris" modification, which extends the body tube about 5 inches above the streamer/parachute bay, and allows for a payload with an Altimeter One to measure altitudes.
After this payload section was tragically lost when the screw-eye/balsa joint failed, I built a newer, lighter and smaller payload section. It is now 3-1/8" vs. 4-1/2", and weighs 9.8 grams. I certianly hope now I can get that extra 12 inches of altitude out of this bird and finally crack that elusive 1200 foot mark!
Originally, I replaced the flimsy crepe paper streamer with plastic one, but the plastic seems to stick to body tube because of static electricity, so I replaced it again with a small 8" parachute. With this parachute it descends at about 9 mph, soft enough for a safe grass landing. The rather small size should prevent this from drifting too much - a real problem considering the height it can attain. (The Iris altimeter payload is named after the Greek god of the rainbow. She is a messenger of the gods, linking the gods with humanity.) This rocket has flown higher than the NY Times Building in NY, the John Hancock Tower, and the Aon Center in Chicago.
| Flight Date: | 2012-05-06 |
| Rocket Name: | Sprint |
| Kit Name: | Estes - Sprint {Kit} (1249) [1970-1983] |
| Flyer's Name: | Rich DeAngelis |
| Motors: | C6-7 |
| Expected Altitude: | 1,200.00 Feet |
| Wind Speed: | 3.00 mph |
| Launch Site: | Penn Manor School Lancaster PA |
| Actual Altitude: | 1,139.00 Feet |
This was the 4th attempt for this rocket to crack 1200 feet. Previously I've recorded 1198 and 1199 feet, so I'm really hungry for that 1200 and I know she can do it. The winds were light when she lit up and accelerated at a peak of 16.2Gs. Acceleration averaged 4.5Gs for the 2.1 second burn. It reached a record speed of 202 mph for this model allowing it to coast for 6.3 seconds more to a slightly disappointing altitude of "only" 1139 feet.
I suppose I was not at my best when I felt the need to brag to a fellow club member (who just launched a 3-stage Farside) that I went higher on a single motor than he did with three motors. Anyway, after apogee the Sprint only descended 23 feet in another 1.3 seconds before ejection at 1116 feet. The tiny 8" chute opened and the model descended at 11 mph to touch down perhaps a good 600 feet downwind. The total flight time was 74.5 seconds. Not only did this rocket break its own speed record, it set a new record for flight duration for any flight of mine. That's my definition of a successful flight.
| Stage | Motor(s) |
|---|---|
| 1 | C6-7 |
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